There is an increasing demand for optical networks and optical communication between nodes of such networks, because the increased global demand for high speed data exchange. For example, the use of the Internet worldwide is ever increasing with a high growth rate in the developing countries around the world. However, many emerging business centers in regions near the Equator are handicapped by poor connectivity to the Internet. These centers are typically located in countries with limited national high bandwidth network infrastructure, and sometimes surrounded by either hostile neighbors or inhospitable terrain that makes terrestrial and undersea cable connections impractical.
Nevertheless, there is a continuing demand for high bandwidth connectivity to the Internet in these countries. Many of the most rapidly growing markets are both near the Equator and poorly connected via undersea cables. For some of the larger countries, the internal network infrastructure is relatively primitive. Furthermore, natural disasters can also disrupt connections, and the ability to rapidly reconfigure a communication network to reconnect the affected areas can be extremely valuable. In addition to the underserved markets, the major global telecom carriers of significant and growing wholesale bandwidth have needs for backup and replacement bandwidth to maintain Quality of Service agreements.
All prior attempts at lasercom in space have used an optical to electrical to optical (O-E-O) approach, with the incoming optical signal converted to an electrical signal and then converted back to an outgoing optical signal. That is, all conventional space optical communications systems have an electronic receiver at each node of the system and therefore require an optical-to-electronic conversion.
Furthermore, the prior art approaches do not package the system in a modular fashion and therefore the resulting system is not practical for use in, for example, space and airborne platforms, because such systems have a substantially greater weight, require more power, and cost more. Accordingly, only one or two of the previous designs can be supported by a commercial spacecraft.
Moreover, conventional embodiments of the payload have separate optical and laser structures with complex interconnect cabling between them. Another conventional approach considered was a distributed approach with laser and electronic components mounted within the bus structure of a spacecraft. However, both of these arrangements prove difficult to manufacture and integrate, because they require a large number of unique parts which is a substantial cost driver.